The present applicant's PCT application PCT/SG99/00119, the disclosure of which is incorporated herein by reference in its entirety, proposes a method of processing signals in which signals received from an array of sensors are subject to a first adaptive filter arranged to enhance a target signal, followed by a second adaptive filter arranged to suppress unwanted signals. The output of the second filter is converted into the frequency domain, and further digital processing is performed in that domain.
The present invention seeks to further enhance the system by incorporating a third adaptive filter in the system and uses a novel method for performing improved signal processing of audio signals that are suitable for speech communication and speech recognition.